Carotid artery angioplasty guiding system

ABSTRACT

A method and apparatus for performing an angioplasty of a patient&#39;s carotid artery includes a placement of a first elongated positioning catheter having a lumen and proximal and distal end portions within a patient&#39;s body so that the distal end portion of the positioning catheter occupies a position within the patient&#39;s aorta next to the patient&#39;s selected carotid artery. The distal end portion of the positioning catheter is curved with a radius of curvature of about 2 cm, for example, and provides a soft distal tip. Using fluoroscopy, a user can manipulate, rotate, and position the positioning catheter until the distal tip enters the carotid artery. A guide wire is then advanced through the lumen of the positioning catheter until the free end portion of the wire reaches the distal tip of the positioning catheter and enters the selected carotid artery. A second catheter is advanced over the positioning catheter, the second catheter being a guiding catheter having a distal end portion. The distal end portion of the guiding catheter is shaped to provide two curved sections or bends. The distal end portion of the guiding catheter includes a central section and a pair of opposed sections. The two bends or curved portions form respective connections between the central section and each of the opposed sections.

SPECIFICATION

Priority of U.S. Provisional Patent Application Ser. No. 60/004,942,filed Oct. 4, 1996, is hereby claimed. That application is herebyincorporated by reference.

SPECIFICATION

Priority of U.S. Provisional Patent Application Ser. No. 60/004,942,filed Oct. 4, 1996, is hereby claimed. That application is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to cardiac catheter devices and moreparticularly to an improved method and apparatus for eliminating aconstriction or narrowing of a patient's carotid artery.

2. General Background

Atherosclerotic stenosis of the extracranial carotid arteries (thearteries on each side of the neck that supply blood to the head andneck) causes a significant portion of the 500,000 strokes that occureach year in the U.S. The superiority of carotid endarterectomy overmedical management has been clearly demonstrated in symptomaticpatients. Recently, the Asymptomatic Carotid Atherosclerosis Studyshowed a marked reduction in the incidence of stroke following carotidendarterectomy in asymptomatic carotid stenosis of >60%. These studieshave provided clear evidence of the benefit of revascularization of thediseased extracranial carotid artery. Carotid endarterectomy isperformed now surgically through an artery in the patient's neck.

Surgery, however, has several limitations. In patients with angina,morbidity and mortality rates as high as 18% have been reported.Endarterectomy is generally confined to the cervical portion of thecarotid artery. Cranial nerve palsies occur in 7.6% to 27% of patients.Restenosis after endarterectomy appears to occur in 10% to 19% ofpatients.

Percutaneous techniques have the potential for being safer, lesstraumatic, more cost effective, usable in patients at high surgicalrisk, and are not limited to the cervical carotid artery. Thesepotential benefits, however, have yet to be realized for the generalpopulation of patients with carotid disease even though percutaneouscarotid balloon angioplasty (PCBA) was first performed in 1980.Angioplasty is a procedure for alleviating blockage of an artery inwhich a balloon tipped catheter is threaded into an artery to a point ofobstruction and inflated to push the vessel open.

Surgeons are presently using catheters designed for coronary angioplastyand peripheral angioplasty. Thus, there exists a need for a cathetersystem specifically designed for carotid arteries.

U.S. Pat. No. 5,449,362 and prior applications, PCT Application no.PCT/US95/06205, and all patents mentioned herein and therein, areincorporated herein by reference.

SUMMARY OF THE INVENTION

The present invention provides a method of performing angioplasty on apatient's carotid artery. The method includes the initial placement of apositioning catheter within a patient's body so that the distal end ofthe positioning catheter occupies a position within the patient's aortanext to a selected carotid artery.

A user (Cardiologist, assistant, or technician, etc.) rotates the distalend of the positioning catheter to position a curved end portion anddistal tip of the positioning catheter at the intersection of thecarotid artery and the aorta. The user then positions the distal tipinto the carotid artery.

A guide wire is then advanced through the lumen of the positioningcatheter until the free end of the wire reaches the distal tip of thepositioning catheter and the carotid artery.

A second (guiding) catheter having a lumen is then advanced over thepositioning catheter. The second catheter has proximal and distal endportions and a lumen that receives the first (positioning) catheter.

The distal end portion of the second catheter includes three sections,including a central section and a pair of opposed sections with twobends forming the connections respectively between the central sectionand the opposed sections. The bends of the guiding catheter position thedistal end at the patient's carotid artery during use. One of the bendsis much larger in curvature and it tracks the patient's aorta during useat a location spaced away from the target carotid artery.

The present invention also provides a catheter apparatus for dilating astenosis in a patient's carotid artery. The apparatus includes a first,positioning catheter having proximal and distal end portions and alumen. The distal end portion of the positioning catheter is curved toprovide a tip portion that enables the user to access a selected one ofthe patient's carotid arteries when the positioning catheter occupiesthe patient's aorta.

The apparatus further includes a guide wire that fits the lumen of thepositioning catheter. The guide wire provides a free end portion thattravels through the lumen of the positioning catheter to the distal endportion thereof so that the guide wire can enter the patient's carotidartery at the distal end of the positioning catheter.

A second catheter (guiding catheter) has proximal and distal endportions and a lumen that enables the guiding catheter to advance overthe positioning catheter during use.

The distal end portion of the guiding catheter has two curved sectionsincluding a first curved section that is closest to the distal tip and asecond curved section that has less curvature than the first curvedsection. The second curved section is spaced away from the distal tipand first curved section.

The distal end portion of the guiding catheter includes a centralsection and a pair of opposed sections positioned on opposite sides ofthe central section.

The central section forms an angle with each of the opposed sections todefine the first and second curved sections, including a first obtuseangle and a second much smaller angle, preferably about 90°. The obtuseangle is preferably about 130°.

During use, the smaller 90° angle bend is positioned adjacent thecarotid artery to be treated. The obtuse angle tracks the patient'saorta at a location spaced away from the carotid artery.

The apparatus of the present invention can include a third catheter witha reinforcing section that fits over the curved portions of the guidingcatheter during use. However, the reinforcing section can also havecorrespondingly shaped curved portions to fit the curved sections of theguiding catheter. Thus, the reinforcing section of the third cathetercan be used to maintain the curvatures of the guiding catheter whenstiff objects such as a stent are routed through/advanced through thelumen of the guiding catheter.

In order to insert a stent, an instrument, a balloon, an atherectomydevice, or a device that will inject a drug, the wire and positioningcatheter are first removed. The user can then deploy selectedinstruments, stents, drugs, balloons, atherectomy devices, etc. via thelumen of the third reinforcing catheter or the lumen of the guidingcatheter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be had to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like parts are given like reference numerals, and wherein:

FIG. 1 is a plan view of the preferred embodiment of the apparatus ofthe present invention shown in use with a pressure tubing system;

FIG. 2 is plan view of the preferred embodiment of the apparatus of thepresent invention showing advancement of the guide sheath over thecarotid guiding catheter to provided added support around the aorticarch;

FIG. 3 is a plan view of the preferred embodiment of the apparatus ofthe present invention showing its use with a Y-type connector andballoon catheter;

FIG. 4 is a plan view of the preferred embodiment of the apparatus ofthe present invention;

FIG. 5 is a partial schematic view of the positioning catheter portionof the preferred embodiment of the apparatus of the present invention;

FIG. 6 is a fragmentary view of the preferred embodiment of theapparatus of the present invention illustrating the carotid guidingcatheter;

FIG. 7 is an illustration of various carotid guiding catheter shapes forthe preferred embodiment of the apparatus of the present invention;

FIG. 8 is a schematic view illustrating the reinforcing sheath portionof the preferred embodiment of the apparatus of the present invention;

FIG. 9 is a schematic view of a patient's aortic arch and the adjacentsubclavian artery, and carotid artery, showing the first method step ofthe present invention in placement of the positioning catheter;

FIG. 10 illustrates the second method step of the method of the presentinvention;

FIG. 11 illustrates the third method step of the method of the presentinvention; and

FIG. 12 illustrates the fourth method step of the method of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT PARTS LIST

20 guide wire

30 carotid artery positioning catheter

31 distal end of the positioning catheter 30

40 carotid guiding catheter

41 primary curve of carotid guiding catheter 40

41A-41H primary curve of carotid guiding catheters 40A-40H

42 distal end of carotid guiding catheter 40

43 secondary curve of carotid guiding catheter 40

43A-43H secondary curve of carotid guiding catheters 40A-40H

50 carotid reinforcing sheath (guide sheath)

51 distal end of carotid reinforcing sheath 50

52 reinforced segment of carotid reinforcing sheath 50

60 commercially available femoral sheath to be located in femoral artery

70 pressure tubing system

80 anchoring device (valve)

90 Y-connector

110 balloon catheter

A patient's aortic arch

C right common carotid artery

L left common carotid artery

S subclavian artery

V left vertebral

The present invention comprises a catheter system for facilitatingpercutaneous angioplasty of the carotid artery and a method of using thecatheter system in performing percutaneous angioplasty of the carotidartery. The carotid arteries are those arteries on the sides of the neckthat supply blood to the head and neck.

In FIGS. 1-4, the catheter system 10 includes a guide wire 20, a carotidpositioning catheter 30, a carotid guiding catheter 40, and a carotidreinforcing sheath 50. In practice, an incision is made in a femoralartery in the patient. As shown in FIGS. 1-3, commercially availablefemoral sheath 60 (having a pressure tubing system 70) is placed throughthe incision into the femoral artery. The positioning catheter 30 isplaced inside the guiding catheter 40, which in turn is placed withinthe reinforcing sheath 50. The guide wire 20 is placed inside thepositioning catheter 30.

In FIGS. 1-3, only proximal portions of the guide wire 20, sheath 50,and catheters 30 and 40 are shown. Only distal portions of the guidewire 20, sheath 50, and catheters 30 and 40 are shown in FIGS. 5-12.

The distal end 31 of the positioning catheter 30 is first advanced tothe patient's aortic arch A (see FIGS. 5 and 9). When the distal end 31of the positioning catheter 30 is adjacent the right subclavian artery S(see FIG. 9), the free distal end 31 of positioning catheter 30 ismanipulated and rotated (using fluoroscopy) to enter the rightsubclavian artery (see FIG. 10). As shown in FIG. 5, the free distal end31 is connected to main portion 32 with a U-shaped portion having aradius of curvature of about 2 cm.

The carotid artery positioning catheter 30 has a relatively straightmain longitudinal portion 32 and has a distal tip portion which iscurved and has a distal tip 31 which extends approximatelyperpendicularly about 4 cm from its main longitudinal portion 32, asshown in FIG. 5.

In the carotid guiding catheter 40 (see FIG. 6), the primary curve 41 ispreferably 3-8 cm from the distal end. There is a, for example, 3 mmsoft tip at the distal end 42. The primary curve 41 is preferably about90 degrees. The secondary curve 43 is 5-10 cm from the primary curve 41and is preferably about 130 degrees. The carotid guiding catheter 40 is,for example, 90-110 cm long and 8-11 Fr.

The guide wire 20 is then advanced through the lumen of positioningcatheter 30 into the subclavian artery S (see FIG. 10) until it reachesthe target area in the carotid artery C. The guiding catheter 40 isadvanced along the positioning catheter 30 and guide wire 20 (see FIG.11) until its distal free end 42 is adjacent the distal end of the guidewire 20.

The reinforcing sheath 50 is then advanced along the guiding catheter 40until its distal end 51 is adjacent the distal end 42 of the guidingcatheter 40 (see FIG. 12), to provide added support around the aorticarch A.

The anchoring device 80 (see FIGS. 1-3) is then tightened to secure thereinforcing sheath 50 to the guiding catheter 40. Once this occurs, theguide wire 20 and positioning catheter 30 are removed, leaving only theguiding catheter 40 and the reinforcing sheath 50 in the patient (seeFIG. 12).

Appropriate medicine can be administered, and appropriate procedures canbe performed, through the guiding catheter 40. For example, aY-connector 90 can be attached to the guiding catheter 40 (see FIG. 3)to allow a balloon catheter 110 to be inserted into the carotid artery.

FIG. 7 shows various shapes for the primary curve (41A-41H) andsecondary curve (43A-43H) of the carotid guiding catheter (catheters40A-40H). In FIG. 7, the primary curve (41A-41H) is about 70 degrees toabout 150 degrees. The angle of the primary curve of the carotid guidingcatheter is dependent on the anatomy of the patient. One chooses anangle which is appropriate for the anatomy of a patient (an angle whichmakes it possible and relativley easy to successfully manuever the tipselectively into the right or left common carotid artery).

In FIG. 7, the secondary curve (43A-43H) of the carotid guiding catheter(catheters 40A-40H) is about 130 degrees. The secondary curve of thecarotid guiding catheter is preferably about 95 degrees to about 165degrees. More preferably, the secondary curve of the carotid guidingcatheter is about 100 degrees to about 160 degrees. Most preferably, thesecondary curve of the carotid guiding catheter is about 120 degrees toabout 140 degrees.

The carotid reinforcing sheath 50 (see FIG. 4) has a distal end 51 whichhas a soft tip which can be, for example, about 3 cm-5 cm (andpreferably 3 cm) long. There is a 10-20 cm long reinforced segment 52 ofthe sheath 50 which extends across the primary and secondary bends 41and 43 of the carotid guiding catheter 40.

The use of the carotid reinforcing sheath 50 allows the guide wire 20 tobe sufficiently flexible that it causes very little, if any, trauma asit is advanced toward the target area in the carotid artery C. Were itnot for the carotid reinforcing sheath 50, the guide wire 20 would needto be strong enough (stiff enough) to provide structural support for thecarotid guiding catheter 40 and to prevent the carotid guiding catheter40 from kinking, or the carotid guiding catheter 40 itself would need tobe made stiffer.

The length of the reinforcing sheath 50 can be, for example, 80-100 cm(or even longer if used on a tall person).

All of the catheters 20, 30, 40 can be manufactured of polyethylene,polyurethane, or other suitable polymers. They can be coated with alubricous material such as polytetrafluoroethylene (PTFE) or hydrophilicpolymer.

The reinforced segments of the guide sheath 50 or guiding catheter 40can be reinforced with a metal such as Nitinal brand metal, stainlesssteel, or other inert metal or polymer. It may be fabricated from memoryalloys or bimetal thermocouples, for example.

Because many varying and different embodiments may be made within thescope of the inventive concept herein taught, and because manymodifications may be made in the embodiments herein detailed inaccordance with the descriptive requirement of the law, it is to beunderstood that the details herein are to be interpreted as illustrativeand not in a limiting sense.

What is claimed as invention is:
 1. A catheter apparatus for dilating astenosis in a patient's carotid artery, comprising;a) a positioningcatheter having proximal and distal end portions and a lumen, the distalend portion being curved to provide a curved distal tip portion thatenables the user to access one of the patient's carotid arteries whenthe distal end portion of the positioning catheter occupies thepatient's aorta; b) a guide wire that fits the lumen of the positioningcatheter; and c) a guiding catheter having proximal and distal endportions and a lumen that enables the guiding catheter to advance overthe positioning catheter during use, the distal end portion of theguiding catheter having two curved sections including a first curvedsection that is closest to the distal tip and a second curved sectionwherein the curved sections position the distal end portion of theguiding catheter at the patient's carotid artery during use.
 2. Thecatheter apparatus of claim 1 wherein the distal end portion of theguiding catheter comprises a central section and a pair of opposedsections that are positioned on opposite sides of the central section,the central section forming an angle with each of the opposed sectionsincluding a first angle and a second obtuse angle.
 3. The catheterapparatus of claim 2 wherein the obtuse angle is between aboutninety-five and one hundred thirty degrees.
 4. The catheter apparatus ofclaim 3 wherein the first angle is between about seventy and one hundredfifty degrees.
 5. The catheter apparatus of claim 4 further comprising athird catheter having proximal and distal end portions and a lumen thatenables the third catheter to advance over the guiding catheter duringuse.
 6. The catheter apparatus of claim 5 wherein the third catheter hasa reinforcing section that fits over the curved portions of the guidingcatheter during use.
 7. The catheter apparatus of claim 5 wherein thethird catheter has a reinforcing section that fits over the curvedportions of the guiding catheter during use, and a soft distal tipportion.
 8. The catheter apparatus of claim 5 wherein the third catheterhas a reinforcing section that fits over the curved portions of theguiding catheter during use, and wherein the combination of the guidingcatheter and third catheter have two spaced apart curved portions, onehaving more curvature than the other.
 9. The catheter apparatus of claim8 wherein the wire and positioning catheter are removable from theguiding catheter so that an instrument can be advanced to a stenosis ofthe patient's carotid artery via the lumen of the guiding catheter. 10.The catheter apparatus of claim 2 wherein the first angle is betweenabout seventy and one hundred fifty degrees.
 11. The catheter apparatusof claim 10 further comprising a third catheter having proximal anddistal end portions and a lumen that enables the third catheter toadvance over the guiding catheter during use.
 12. The catheter apparatusof claim 11 wherein the third catheter has a reinforcing section thatfits over the curved portions of the guiding catheter during use. 13.The catheter apparatus of claim 11 wherein the third catheter has areinforcing section that fits over the curved portions of the guidingcatheter during use, and a soft distal tip portion.
 14. The catheterapparatus of claim 11 wherein the third catheter has a reinforcingsection that fits over the curved portions of the guiding catheterduring use, and wherein the combination of the guiding catheter andthird catheter have two spaced apart curved portions, one having morecurvature than the other.
 15. The catheter apparatus of claim 14 whereinthe wire and positioning catheter are removable from the guidingcatheter so that an instrument can be advanced to a stenosis of thepatient's carotid artery via the lumen of the guiding catheter.
 16. Thecatheter apparatus of claim 1 further comprising a third catheter havingproximal and distal end portions and a lumen that enables the thirdcatheter to advance over the guiding catheter during use.
 17. Thecatheter apparatus of claim 16 wherein the third catheter has areinforcing section that fits over the curved portions of the guidingcatheter during use.
 18. The catheter apparatus of claim 16 wherein thethird catheter has a reinforcing section that fits over the curvedportions of the guiding catheter during use, and a soft distal tipportion.
 19. The catheter apparatus of claim 16 wherein the thirdcatheter has a reinforcing section that fits over the curved portions ofthe guiding catheter during use, and wherein the combination of theguiding catheter and third catheter have two spaced apart curvedportions, one having more curvature than the other.
 20. The catheterapparatus of claim 1 wherein the wire and positioning catheter areremovable from the guiding catheter so that an instrument can beadvanced to a stenosis of the patient's carotid artery via the lumen ofthe guiding catheter.